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1.
运用景观生态学原理,借助M apInfo技术,选取斑块密度、边缘密度、景观多样性、景观优势度等指标,分析塞罕坝地区不同地貌下景观类型的空间分布和空间格局特征,深入探讨了森林景观的林分类型、起源和分布特点,结果显示塞罕坝山地的斑块密度、边缘密度、破碎度,分别都高于沙地和曼甸,但山地的景观多样性低于曼甸和沙地。森林景观以落叶针叶林面积最大,为38 306.7 hm2,其次是阔叶林和常绿针叶林,分别为16 470.5hm2,9 455.5hm2,灌木林和混交林面积最小。曼甸以落叶针叶林景观优势度最高,且多为落叶松人工纯林;山地以落叶针叶林和阔叶林景观优势度较高,其中,阔叶林多为天然次生林,树种以桦树为主;沙地以落叶针叶林和常绿针叶林优势度较高,其常绿针叶林多为人工樟子松纯林。  相似文献   

2.
The joint and independent effects of dominant tree species, forest patch spatial attributes, and forest structure and management as drivers of plant species richness and composition in small forest patches scattered within an intensive agricultural landscape were addressed.In a landscape with scattered urban and intensive dairy agricultural areas in north-west Portugal, within which small forest patches (dominated by pines, eucalypts, or both) represent semi-natural habitat islands, 50 small forest patches, with areas ranging between 0.3 and 3 ha, were selected and surveyed for vascular plant diversity, within dairy farming landscape mosaics dominated by annual forage crops. Explanatory variables were composed of three datasets derived either from GIS mapping or field observations: forest type (dominant tree species), forest patch spatial attributes (patch area and shape index), and measures of forest management and structure (diameter at breast height, tree density per hectare, and percentage cover of vegetation strata). Variations in these forest patch attributes were assessed across forest types, and related to measures of plant diversity (total, native, alien, woody, and herbaceous species richness). Redundancy analysis with variance partitioning was applied to evaluate the joint and independent effects of the three sets of variables on species assemblages. The recent shift in canopy dominance from pine to eucalypt observed in the region appears to be related to a (nonsignificant) tendency for the increase of patch area and to the decrease of patch complexity, as well as several changes in forest structure and management, expressed as a trend to denser tree canopies and lower cover of understory plants. Dominant tree species and attributes related to forest structure and management were the most important factors determining plant diversity. The joint effect of the dominant tree species and forest structure and management resulted in lower levels of plant species richness in eucalypt plantations. These were also more prone to invasion by alien species, probably due to decreased biotic resistance from unsaturated native plant assemblages. Our results draw attention to the importance of dominant tree species and management practices for the maintenance of plant diversity levels (species richness and composition) in dairy landscape mosaics, highlighting the importance of the remnants of semi-natural forests as refuges for plant diversity in the landscape context. Nonetheless, forest plant diversity could further be fostered by promoting naturalness of pine stands and the regeneration of native oak woodlands in some forest areas. This would also diversify the range of ecosystem services that could be provided by forest areas in these peri-urban farmlands.  相似文献   

3.
根据土地类型和植被特征划分景观类型,然后运用GIS软件进行数字化,并计算斑块指标。分析结果表明:南湾国家级森林公园森林景观共有松林、杉林、栎林、竹林、板栗林和茶园等6种类型。各类型的面积、周长及斑块数都不均衡;松、杉林景观处于主导地位;茶园形状最复杂,而松、杉林景观破碎化程度最高,受人为因素影响最大。  相似文献   

4.
The purpose of this work was to study fragmentation of forest formations (mesophytic forest, riparian woodland and savannah vegetation (cerrado)) in a 15,774-ha study area located in the Municipal District of Botucatu in Southeastern Brazil (São Paulo State). A land use and land cover map was made from a color composition of a Landsat-5 thematic mapper (TM) image. The edge effect caused by habitat fragmentation was assessed by overlaying, on a geographic information system (GIS), the land use and land cover data with the spectral ratio. The degree of habitat fragmentation was analyzed by deriving: 1. mean patch area and perimeter; 2. patch number and density; 3. perimeter-area ratio, fractal dimension (D), and shape diversity index (SI); and 4. distance between patches and dispersion index (R). In addition, the folowing relationships were modeled: 1. distribution of natural vegetation patch sizes; 2. perimeter-area relationship and the number and area of natural vegetation patches; 3. edge effect caused by habitat fragmentation. The values of R indicated that savannah patches (R = 0.86) were aggregated while patches of natural vegetation as a whole (R = 1.02) were randomly dispersed in the landscape. There was a high frequency of small patches in the landscape whereas large patches were rare. In the perimeter-area relationship, there was no sign of scale distinction in the patch shapes. In the patch number-landscape area relationship, D, though apparently scale-dependent, tends to be constant as area increases. This phenomenon was correlated with the tendency to reach a constant density as the working scale was increased. On the edge effect analysis, the edge-center distance was properly estimated by a model in which the edge-center distance was considered a function of the total patch area and the SI.  相似文献   

5.
Abstract

Altered forest landscape structure has been suggested as a possible cause for the decline of some specialized forest species in Fennoscandia. Here, we present a time series of boreal landscape changes in 1954–2005 in 16 5×5 km sub-areas in Sweden, based on aerial photo interpretation. We explored how coniferous forest vegetation types, known to be important to some specialized forest species, have been fragmented and also declined in mean patch size and their proportion of the landscape. We divided the studied area into a western (inland) and eastern (coastal) part based on different timing of landscape changes. The mean patch area of forest >50 yrs declined from ~90 ha in 1954 to 10 ha in 2005 in the inland and from 30 ha to only ~5 ha patches in the coastal area. Common vegetation types, such as mesic and moist forest >50 yrs showed a similar declining trend. In our study area, the long-term decline 1971–2005 of the specialized forest species grey-sided vole (Myodes rufocanus) coincided with the decline of mean focal patch size of forest >50 yrs. The data presented here can be used in further analyses of species–landscape interactions along spatiotemporal gradients.  相似文献   

6.
信宜市土地利用景观格局研究   总被引:1,自引:0,他引:1  
以广东省信宜市为研究区,利用patch analyst景观格局分析软件,选取斑块数目、斑块面积、斑块密度、平均斑块大小、斑块面积标准差、斑块面积变异系数、平均斑块形状指数、面积加权平均斑块形状指数、平均斑块分维数、面积加权平均斑块分维数、破碎度、均匀度和多样性指数等指标,对信宜市土地利用景观格局进行分析.结果表明:各类...  相似文献   

7.
利用2006年勐腊县森林资源二类调查数据,在ARCGIS 9和FRAGSTAT 3.3软件支持下,选取有代表性的林地景观格局指标:景观斑块密度、分维数、聚集度、破碎化、多样性指数、优势度、均匀度等来描述勐腊县林地景观格局.结果显示研究区优势度较低,异质性不高;景观中有一定的优势类型,以自然景观占优势.橡胶林景观破碎化程度较低,斑块较为完整.混交林景观连通性好,结构稳定.半自然景观、农地景观破碎化程度较高.  相似文献   

8.
利用2006年勐腊县森林资源二类调查数据,在ARCGIS9和FRAGSTAT3.3软件支持下,选取有代表性的林地景观格局指标:景观斑块密度、分维数、聚集度、破碎化、多样性指数、优势度、均匀度等来描述勐腊县林地景观格局。结果显示研究区优势度较低,异质性不高;景观中有一定的优势类型,以自然景观占优势。橡胶林景现破碎化程度较低,斑块较为完整。混交林景观连通性好,结构稳定。半自然景观、农地景观破碎化程度较高。  相似文献   

9.
为更好地实现八英庄林场森林资源的优化配置,以河北省木兰围场国有林场管理局八英庄林场2010年和2015年2期地形图、遥感图像及二类调查数据为基础,运用ArcGIS10.0和Fragstats4.2软件,对砬沿沟流域森林景观变化进行分析。砬沿沟流域按一级景观分类划分,斑块类型共5类,有林地斑块面积由473.95hm~2增加为500.88hm~2,其他斑块面积相对减小;有林地的景观形状指数、散布与并列指数减小,分别由3.008 1、59.106 6降为2.481 6、49.060 4;景观多样性由0.426 9减小为0.233 4,说明各斑块的聚集程度有所增加,各斑块之间的连通性有所提高。砬沿沟流域按二级景观分类划分,在有林地类型中,2010年和2015年斑块类型都为5类,到2015年山杏林斑块消失,新增云杉林斑块;2010至2015年华北落叶松林斑块面积、斑块景观形状指数均增加,山杨林斑块面积、斑块景观形状指数均减小。砬沿沟流域森林景观香农多样性指数由1.602 7降为1.389 2。除去一级景观分类中有林地斑块破碎度减小,其他无论是一级景观分类还是二级景观分类,各斑块破碎度都有不同程度的增加,说明近5a一级、二级斑块在总数上有所增加,并且增加的斑块相对独立,并不连续。  相似文献   

10.
基于森林资源二类调查数据的森林景观分类研究   总被引:16,自引:1,他引:15  
以吉林省汪清林业局金沟岭林场为例 ,提出一种基于森林资源二类调查数据的景观要素分类方法。选取优势树种 (组 )、海拔、坡度、坡向和太阳辐射强度作为分类因子 ,在GIS技术支持下 ,按分类因子分割林场森林景观空间为 975 7个空间基本单元 ,建立起量化的、与植被和环境因子相关的森林景观空间基本单元数据库 ,在此基础上采用聚类分析方法把所有基本单元聚合为不同相似水平上的景观要素类型 ,结合生态特征和经营需要对聚类结果进行分析并最终确定了 7种景观要素类型 ,生成了景观要素类型斑块图。斑块特征和空间格局分析结果表明 :该林区森林景观中以小斑块要素比例最大 ,中、小斑块数占总斑块数的 90 %。针阔混交林具有最大的面积、平均斑块面积、斑块周长、最大生境面积和内部生境指数 ,是该地区受人为干扰相对较小、仍需要进行保护的景观要素类型。在森林经营中 ,应注意保护大型斑块的景观要素类型  相似文献   

11.
Forest structure changes continuously by natural and anthropogenic effects. Because the level of goods and services provided by forest ecosystems are related to this structure, some attributes have to be controlled while they are being managed. In this paper we describe the long-term temporal changes in land area and landscape metrics related to different land uses of a managed forest in Turkey. The study was carried out for the Daday Forest Planning Unit located in the west Black Sea region of northern Turkey. The total area is 16,813 ha and besides wood production, it is managed for erosion control, public health, aesthetics, and recreation. Stand type maps that were constructed in 1970, 1989, 1999, and 2010 were used in this analysis. Transition matrixes that illustrate area changes among cover types and temporal changes on some landscape metrics were obtained using Geographic Information Systems. Stands were separated into small patches, and thus the number of patches increased nearly two-fold between 1970 and 2010. The total forest edge increased and through the associated fragmentation, the amount of core forest area decreased at the landscape scale. Landscape metrics were applied to digitized versions of historical maps to assess how forest area changed. Human use of the land has changed, forest management practices have evolved, and these along with natural forest growth have contributed to interesting changes in landscape character.  相似文献   

12.
云南省个旧市城市森林景观格局的分析与评价   总被引:1,自引:0,他引:1  
采用景观指数法对个旧市城市森林5种景观类型的格局进行了分析。所使用的景观指数包括斑块特征指标、景观多样性指标、景观空间关系指标等。结果表明:个旧市城市的森林景观多样性指数较低,各景观类型的优势度有较大差异,其整体上,异质性较差。而各景观类型拥有的斑块数分布很不均匀,从面积和斑块数来看,以公共绿地的斑块数最多,面积最大,为个旧市城市森林的主导景观。公共绿地和专用绿地较近于均匀分布格局,生产绿地和风景园林接近于随机分布格局。  相似文献   

13.
Fuel treatments for reducing fire risk are necessarily tied to the landscape structure including forest composition and configuration. Thus understanding the relationships between landscape structure and burn severity is important for developing guidelines and management strategies for fire-resilient forests. The goal of this study was to investigate the relationship between landscape structure as described by spatial pattern metrics and burn severity at the landscape and class levels. In 2000, a mostly severe fire burned 16,210 ha of dense forest located in Samchuck on the east coast of the Korean peninsula. Spatial pattern metrics including patch density, largest patch index, mean shape index, area-weighted mean shape index, Euclidean nearest neighborhood distance, and Shannon's diversity index, as well as topographic characteristics of slope and elevation, were correlated with burn severity based on delta Normalized Burn Ratio (dNBR) assessments. Regression tree analysis was also carried out with the same variables to avoid spatial autocorrelation and to reveal the relative importance of variables to burn severity. The results of this study strongly suggest that both composition and configuration of the forest cover patches are closely tied to burn severity. In particular, both the correlation analysis and regression tree analysis indicated that the area of red pine tree forest cover was the most significant factor in explaining the variance of burn severity. Topography and spatial configuration of forest cover patches were also significantly related to burn severity. The heterogeneity of forests also had a significant influence on burn severity. To reduce fire risk and increase the fire resilience of forests, forest managers and agencies need to consider enhancing the heterogeneity of forests when implementing fuel treatment schemes. However, such fuel treatments for landscape structure may only be effective under moderate weather conditions.  相似文献   

14.
贵州省湄潭县属于典型的适竹少竹县,现有竹林面积4 691.3 hm2,新增竹林潜力较大,可以通过退耕还竹、低效林改竹和"四旁地"造竹新增竹林15 600 hm2,达到20 291.3 hm2的竹林总量。发展竹产业存在竹林分布零散、利用率不高、加工基础薄弱等问题,但也有立地条件和土地资源等适宜竹林培育的优势条件。由此文章提出了竹产业发展的对策:分类培育,提高现有竹林质量;挖掘土地潜力,规划培育笋、材、景观兼用竹林;扶持笋竹加工,开发竹产品市场;强化科技服务,保障竹产业技术需求;设置管理机构,有序推动竹产业发展。  相似文献   

15.
以ALOS获得的影像(10 m)为原始数据,借助ArcGIS等软件和景观生态学方法分析了科尔沁沙地疏林典型分布区的景观格局特征。结果表明:①研究区景观破碎化程度不高,类型较单一;另外景观以少数几个大斑块为主,并且斑块的形状相对简单且不稳定。②农田和蒙古黄榆疏林是该地区的主要景观类型,分别占到研究区总面积的33.5921%和20.2617%;同时,虽然农田斑块穿插分布于蒙古黄榆疏林斑块之间,但是蒙古黄榆疏林仍然具有大面积成片分布。③研究区流动沙地分布面积较小、斑块数最多、平均斑块面积最小,以固定沙地和半固定沙地为主。  相似文献   

16.
基于2013年安化县森林资源规划设计调查数据、2017年林地变更调查数据,利用地理信息系统软件及景观格局指数计算软件,分析安化县天然林景观格局特征,对安化县天然林空间格局与动态演变进行研究。结果表明:安化县天然林主要是由竹林和阔叶林组成,占安化县天然林总面积的80%以上;从天然林整体变化情况来看,2013—2017年安化县天然林面积整体呈减少趋势,各森林类型斑块密度、景观类型比略有变化,天然林景观整体变化不大,景观维持平衡稳定;天然林景观在空间分布趋于聚集分布,连接状况趋于更佳,天然林斑块的形状趋于更规则、更复杂,景观格局趋于更好。  相似文献   

17.
景观格局是由自然或人为形成的一系列大小、形状各异,排列不同的景观要素共同作用的结果.利用2005年MODIS卫星数据,经过一系列处理后得到湖南省景观图.利用决策树分类法将研究区分为5种景观类型:水、自然植被、耕地、城镇用地、其它用地.选取斑块数、斑块密度、破碎度、斑块分维数、多样性指数、优势度、均匀度、聚集度、分离度等景观指数,从斑块、斑块类型和景观3个层次上对研究区景观格局进行定量分析.结果表明:湖南省景观斑块共39357块,总面积为21.1984万km2;在5种景观类型中,植被和耕地是主要景观类型,占研究区总面积的88.38%;湖南省景观多样性程度低,且斑块空间形状简单.  相似文献   

18.
以河北省木兰围场国有林场管理局桃山林场施业区内的森林资源为对象,利用GIS技术对其森林景观及分布规律进行分析,结果表明:桃山林场森林景观以混交林为主体,其面积占景观总面积的60.42%,斑块数量占景观斑块总数量的29.01%,优势度达到3.474 5。在斑块规模中,以混交林斑块最大,纯林和荒山荒地也有较大规模,疏林地也有相当规模分布,未成林造林地、宜林沙荒地、灌木林、耕地和其它用地景观规模最小;各类斑块的极差值均较大,斑块大小的分化较强烈。混交林的形状最复杂;其次是未成林造林地、纯林、荒山荒地、灌木林、宜林沙荒地、耕地和疏林地;其它用地的形状规整,边缘形状简单,说明这类景观斑块受人为干较严重。  相似文献   

19.
This paper contributes to the discussion on current issues in methodologies of mapping land cover in the agro-silvo-pastoral landscapes of the Mediterranean. These landscapes, characterized by intermixed land use and indefinite boundaries, require particular attention in applying the patch-corridor-matrix model when classifying patches and their delineation. In a case study area in southeast Portugal, mainly characterized by agro-silvo pastoral systems, the land cover for 1990 has been mapped. The paper discusses the consequences of the complexity of some Mediterranean land use systems for land cover mapping dealing with detailed landscape dynamics. Within this scope a land cover mapping project in a small case study area is compared with the mapping undertaken within a national land cover database. Both studies were carried out on the same scale and through visual interpretation of aerial photographs. Differences in land cover classification and allocation are explored using matrix with levels of agreement. Recommendations for future land cover mapping projects are: the application of fuzzy approaches to land cover mapping in agro-silvo-pastoral landscapes should be explored and land cover classifications should be standardized in order to enhance consistency between databases. On the other hand, the fuzziness of the boundaries in this kind of landscapes is inherent to the system and should be accepted as such. The accompanying uncertainties should be taken into account when undertaking landscape analysis on the basis of land cover data.  相似文献   

20.
Sandy forest-steppe ecotone in Baiyinaobao Natural Reserve of Inner Mongolia Autonomous Region of China is one of the special landscape types in forest-steppe vegetation zone in China. Vegetation landscape types, landscape patches and patch size were measured by the field investigation, forest photograph, and airscape. The structure of landscape patches in sandy forest-steppe ecotone, including composition structure, and size structure, was studied and the dynamics and transformation of landscape patches were analyzed. The data obtained in this study could provide theoretical basis for the research on vegetation landscape in forest-steppe ecotones and other vegetation types.  相似文献   

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